First off don't touch the cat

Now about the scratches, if you can't feel the scratch with your thumbnail just use some cleaner wax (Mequiars) and if you can feel it, try some Mequiars Scratch-X

I'd be pissed off too, but taking it out on the cat, even if you saw the cat do it, will bring you nothing but bad carma

Stop and think about it, maybe some other varmit got in there, rat, raccoon, etc. Good luck with your car!